There is a great demand for cost effective automated systems for manufacturing structures using advanced composite materials, e.g. thermoplastic composite materials. A cost analysis has shown that the layup of these materials is the most labor-intensive operation. Layup consists of building up ply layers, stacked up in different fiber orientations to give desired mechanical properties. Each distinct layer is created by placing several strips of material next to one another. Accuracy requirements for layup are high, and human inaccuracies result in a high final part reject rate. To decrease human labor content and increase overall quality, automated layup systems are desirable. To accurately place strips of material next to one another, it is necessary to detect the edge of a ply of material. Optical sensors could resolve very small distances and dimensions but are unreliable because of their high sensitivity to surface waviness, a common condition of ply material. In addition, optical sensors normally require sufficient contrast not often present between layers of plies to be assembled and frequently the plies are black or dark in color, further exacerbating the problem for optical sensors.